Vanadate, a sodium-potassium ATPase inhibitor and adenylate cyclase stimulator, was found to lower intraocular pressure when topically applied to the eyes of rabbits and monkeys. As this class of compound may be useful in the treatment of glaucoma, the present proposal will study vanadate's efficacy, toxicity and mode of action in the eyes of monkeys. Single and multiple dose-response studies will be carried out measuring intraocular pressure, tonographic outflow facility, aqueous flow by fluorophotometry and episcleral venous pressure in the anesthetized monkey. The effect of vanadate on aqueous and/or ciliary body levels of cyclic AMP, adenylate cyclase and (Na plus K)-ATPase will be measured and correlated with its effect on aqueous humor dynamics. The intraocular pressure effect of vanadate treatment of monkey eyes made glaucomatous by laser burning of the outflow pathways will be examined.